A Computer Assisted Instruction module will make it possible for a student to quickly learn and review the command protocols of the major commercial vendors. Simulation of system performance and actual system use both generate costs inappropriate for the learning of command languages, and should be reserved for instruction in search technique after the achievement of language mastery. We propose to design, test and disseminate a Drill and Practice CAI module for command familiarization in the NLM, SDC, BRS and Lockheed languages. The program will provide for easy update given system changes, and be available for use on either microcomputers or mainframe equipment. Access to Health related literature currently requires at least a working knowledge of the protocols of all four systems.